#3: Fix connection loss to Sun2000 (#4)

application/routes.py

@@ -45,11 +45,8 @@ def post_register_values() -> Response:
     register_names = request.get_json()['registers']
     registers = utilities.validate_registers(equipment, register_names)
 
-    register_data = []
-    for register in registers:
-        register_data.append(utilities.get_register_data(register))
-
-    response = {'equipment': equipment.value, 'registers': register_data}
+    registers_data = utilities.get_registers_data(registers)
+    response = {'equipment': equipment.value, 'registers': registers_data}
 
     return jsonify(response)
 

application/util.py

@@ -33,12 +33,16 @@ def __init__(self, app: Flask):
         self.logger.info(f'Log level set to {self.config[ENV_LOG_LEVEL]}')
 
         self.sun2000 = inverter.Sun2000(self.config[ENV_INVERTER_HOST], self.config[ENV_INVERTER_PORT])
-        self.sun2000.connect()
-        if not self.sun2000.connected:
-            exit('Connection to inverter could not be established')
+        self.check_inverter_connection()
 
         self.logger.info('Ready to accept requests')
 
+    def check_inverter_connection(self) -> None:
+        self.sun2000.connect()
+        if not self.sun2000.isConnected():
+            exit('Connection to inverter could not be established')
+        self.sun2000.disconnect()
+
     def validate_auth_header(self) -> None:
         api_key = request.headers.get('x-api-key')
         if api_key is None or api_key not in self.config[ENV_ACCEPTED_API_KEYS]:
@@ -74,6 +78,19 @@ def validate_registers(self, equipment: Equipment, register_names: List[str]) ->
 
         return registers
 
+    def get_registers_data(self, registers: List[Union[InverterEquipmentRegister, BatteryEquipmentRegister, MeterEquipmentRegister]]) -> List[dict]:
+        self.sun2000.connect()
+        if not self.sun2000.isConnected():
+            abort(502, 'Connection to inverter could not be established')
+
+        registers_data = []
+        for register in registers:
+            registers_data.append(self.get_register_data(register))
+
+        self.sun2000.disconnect()
+
+        return registers_data
+
     def get_register_data(self, register: Union[InverterEquipmentRegister, BatteryEquipmentRegister, MeterEquipmentRegister]) -> dict:
         self.logger.debug(f'Reading data for register {register.name}')
         register_definition = register.value

docs/api-specification.yml

@@ -35,6 +35,8 @@ paths:
               examples:
                 No Equipment Error:
                   $ref: '#/components/examples/NoEquipmentError'
+                Invalid Equipment Error:
+                  $ref: '#/components/examples/InvalidEquipmentError'
         401:
           description: Unauthorized
           content:
@@ -62,6 +64,12 @@ paths:
               schema:
                 $ref: '#/components/schemas/Error'
               examples:
+                No Equipment Error:
+                  $ref: '#/components/examples/NoEquipmentError'
+                Invalid Equipment Error:
+                  $ref: '#/components/examples/InvalidEquipmentError'
+                No Register Error:
+                  $ref: '#/components/examples/NoRegistersError'
                 Invalid Register Error:
                   $ref: '#/components/examples/InvalidRegisterError'
         401:
@@ -73,6 +81,15 @@ paths:
               examples:
                 Unauthorized:
                   $ref: '#/components/examples/UnauthorizedError'
+        502:
+          description: Bad Gateway
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/Error'
+              examples:
+                Inverter Connection Error:
+                  $ref: '#/components/examples/InverterConnectionError'
 components:
   securitySchemes:
     ApiKeyAuth:
@@ -316,6 +333,10 @@ components:
       description: Invalid value for equipment given
       value:
         message: Invalid value for equipment
+    NoRegistersError:
+      description: No registers given
+      value:
+        message: No value for registers
     InvalidRegisterError:
       description: Invalid register name given
       value:
@@ -324,3 +345,7 @@ components:
       description: Unauthorized access
       value:
         message: No or invalid API-key provided
+    InverterConnectionError:
+      description: Error connecting to inverter
+      value:
+        message: Connection to inverter could not be established

requirements.txt

@@ -1,2 +1,2 @@
-sun2000_modbus==1.3.0
+sun2000_modbus==2.0.0
 Flask==2.2.2

tests/sun2000mock.py

@@ -2,11 +2,11 @@
 
 
 def connect_success(self):
-    self.connected = True
+    return True
 
 
 def connect_fail(self):
-    self.connected = False
+    return False
 
 
 MockedRawResponses = {

tests/test_main.py

@@ -12,10 +12,13 @@ class MainTest(unittest.TestCase):
     @patch(
         'sun2000_modbus.inverter.Sun2000.connect', sun2000mock.connect_success
     )
+    @patch(
+        'sun2000_modbus.inverter.Sun2000.isConnected', sun2000mock.connect_success
+    )
     def setUp(self) -> None:
         test_config = {
-            'INVERTER_HOST': '192.168.200.1',
-            'INVERTER_PORT': 6607,
+            'INVERTER_HOST': '1.2.3.4',
+            'INVERTER_PORT': 502,
             'ACCEPTED_API_KEYS': '12345,98765',
             'LOG_LEVEL': 'DEBUG'
         }
@@ -28,7 +31,7 @@ def test_unauthorized_access_to_GET_registers_returns_401(self) -> None:
         self.assertEqual(401, response.status_code)
         self.assertEqual({'message': 'No or invalid API-key provided'}, response.get_json())
 
-    def test_any_api_key_is_valid(self) -> None:
+    def test_any_defined_api_key_is_valid(self) -> None:
         # Testing first API Key 12345
         response = self.client.get('/registers', query_string={'equipment': 'inverter'}, headers={'x-api-key': '12345'})
 
@@ -152,6 +155,12 @@ def test_providing_no_or_invalid_registers_calling_POST_registervalues_returns_4
         self.assertEqual(400, response.status_code)
         self.assertEqual({'message': 'At least one invalid register passed'}, response.get_json())
 
+    @patch(
+        'sun2000_modbus.inverter.Sun2000.connect', sun2000mock.connect_success
+    )
+    @patch(
+        'sun2000_modbus.inverter.Sun2000.isConnected', sun2000mock.connect_success
+    )
     @patch(
         'sun2000_modbus.inverter.Sun2000.read_raw_value', sun2000mock.mock_read_raw_value
     )
@@ -171,9 +180,9 @@ def test_calling_POST_registervalues_for_inverter_equipment_returns_requested_re
                 {
                     'name': 'RatedPower',
                     'type': 'number',
-                    'unit': 'kW',
+                    'unit': 'W',
                     'value': '10000',
-                    'gain': 1000
+                    'gain': 1
                 },
                 {
                     'name': 'State1',
@@ -198,6 +207,12 @@ def test_calling_POST_registervalues_for_inverter_equipment_returns_requested_re
         self.assertEqual(200, response.status_code)
         self.assertEqual(expected_response_json, response.get_json())
 
+    @patch(
+        'sun2000_modbus.inverter.Sun2000.connect', sun2000mock.connect_success
+    )
+    @patch(
+        'sun2000_modbus.inverter.Sun2000.isConnected', sun2000mock.connect_success
+    )
     @patch(
         'sun2000_modbus.inverter.Sun2000.read_raw_value', sun2000mock.mock_read_raw_value
     )
@@ -229,6 +244,12 @@ def test_calling_POST_registervalues_for_battery_equipment_returns_requested_reg
         self.assertEqual(200, response.status_code)
         self.assertEqual(expected_response_json, response.get_json())
 
+    @patch(
+        'sun2000_modbus.inverter.Sun2000.connect', sun2000mock.connect_success
+    )
+    @patch(
+        'sun2000_modbus.inverter.Sun2000.isConnected', sun2000mock.connect_success
+    )
     @patch(
         'sun2000_modbus.inverter.Sun2000.read_raw_value', sun2000mock.mock_read_raw_value
     )
@@ -261,6 +282,20 @@ def test_calling_POST_registervalues_for_meter_equipment_returns_requested_regis
         self.assertEqual(200, response.status_code)
         self.assertEqual(expected_response_json, response.get_json())
 
+    @patch(
+        'sun2000_modbus.inverter.Sun2000.connect', sun2000mock.connect_fail
+    )
+    @patch(
+        'sun2000_modbus.inverter.Sun2000.isConnected', sun2000mock.connect_fail
+    )
+    def test_calling_POST_registervalues_when_inverter_connection_fails_returns_502(self) -> None:
+        registers = ['Model']
+        response = self.client.post('/register-values', data=json.dumps({'equipment': 'inverter', 'registers': registers}), content_type='application/json',
+                                    headers={'x-api-key': '12345'})
+
+        self.assertEqual(502, response.status_code)
+        self.assertEqual({'message': 'Connection to inverter could not be established'}, response.get_json())
+
     def test_calling_GET_health_returns_204(self) -> None:
         response = self.client.get('/health')
 
@@ -274,8 +309,8 @@ class ConnectionFailTest(unittest.TestCase):
     )
     def test_connection_to_inverter_fails_application_exits(self) -> None:
         test_config = {
-            'INVERTER_HOST': '192.168.200.1',
-            'INVERTER_PORT': 6607,
+            'INVERTER_HOST': '1.2.3.4',
+            'INVERTER_PORT': 502,
             'ACCEPTED_API_KEYS': '12345,98765',
             'LOG_LEVEL': 'DEBUG'
         }